package com.mybatis.example.dao.utils;


//sqlSessionFactory  --> sqlSession

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class MyBatisUtils {
    private  static SqlSessionFactory sqlSessionFactory;
    //静态代码块，程序一运行就加载
    static{
        try{
            //使用MyBatis第一步：获取sqlSessionFactory对象
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        }catch(IOException e){
            e.printStackTrace();
        }
    }

//既然有了SqlSessionFactory,顾名思义，我们可以从中获得SqlSession的示例了
//SqlSession 完全包含了面向数据库执行SQL命令所需的所有方法
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }


}
